Project Summary The HIV crisis in Bangkok men who have sex with men (MSM) is volatile with 31% HIV-infected and HIV incidence unbridled and ranging from 8.8% to 12.2% annually in young MSM (YMSM) aged 15-24 years. Consequently, HIV incidence in Bangkok YMSM is Asia?s highest, and in the absence of effective primary and secondary HIV prevention, will continue to increase. Scaling up ART has become the highest priority in responding to this crisis in Thailand. However, data are not available on the HIV care continuum, thus severely limiting critical information needed to design evidence-based secondary prevention interventions for linkage, retention and reengagement in HIV care. In accordance with the R21 funding mechanism, this exploratory study seeks to use the adapted socio-ecological framework to 1) conduct formative research with +YMSM, HIV clinicians and CBO leaders to investigatethe multi-level factors related to the HIV care continuum in Bangkok +YMSM; and 2) quantify the HIV care continuum in +YMSM, and examine the associated facilitators and barriers through a 9-month longitudinal, virtual cohort. A sub aim is to assess the feasibility of an online +YMSM cohort for future online intervention trials. Data from this proposed study by a new investigator will identify which secondary prevention strategies must be scaled in order to meet UNAIDS? 90-90-90 goals. Findings from this study will not only fill critical gaps in the HIV care continuum literature, it will identify subgroups of +YMSM who are most left out from the health system and to whom targeted secondary prevention interventions should be developed.